Wound dressings and systems for effluent management of topical wound therapy and related methods

ABSTRACT

This disclosure includes wound dressings and systems for effluent management of topical wound therapy and related methods. Some devices, which are configured to dilute therapeutic gas effluent flowing from a dressing, comprise a therapeutic gas source configured to provide therapeutic gas to the dressing; a container comprising a sidewall that defines a chamber configured to receive therapeutic gas effluent from the dressing; a negative pressure source configured to be coupled to the container such that the negative pressure source can be activated to draw fluid from the dressing through the chamber of the container; and a diluent gas source configured to deliver a diluent gas to dilute therapeutic gas effluent before the therapeutic gas effluent enters the negative pressure source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/577,505, filed Oct. 26, 2017, the contents of which is incorporatedinto the present application in its entirety.

BACKGROUND 1. Field of Invention

The present invention relates generally to wound dressings, and morespecifically, but not by way of limitation, to wound dressings andsystems for effluent management of topical wound therapy and relatedmethods.

2. Description of Related Art

Clinical studies and practice have shown that topical applications oftherapeutic gas, such as, for example, oxygen, can improve woundhealing, especially in chronic wounds. Topical applications oftherapeutic gas can reduce tissue inflammation and/or improve tissueproliferation (e.g., improve collagen synthesis, growth factorproduction, angiogenesis, and/or the like).

The functional integration of technology to deliver negative pressurewound therapy (NPWT) and topical oxygen therapy presents challenges forthe dissipation of oxygen effluent that exits a dressing and returns toa therapy device. For example, because oxygen effluent contains a highpurity of oxygen (e.g., greater than 80 percent), the effluent can actas an accelerant to an open flame. As such, the accumulation ofhigh-purity oxygen effluent in a therapy device may be undesirableand/or potentially hazardous.

Thus, while the clinical benefits of topical applications of therapeuticgas, and in particular, therapeutic oxygen, are known, proper and safemanagement of therapeutic oxygen effluent may benefit healthcareproviders, caregivers, and patients.

SUMMARY

Some embodiments of the present devices, which are configured to dilutetherapeutic gas effluent flowing from a dressing, comprise a therapeuticgas source configured to provide therapeutic gas to the dressing; afirst outlet configured to be in fluid communication with thetherapeutic gas source; a container comprising a sidewall that defines achamber configured to receive therapeutic gas effluent from thedressing; a first inlet configured to be in fluid communication with thechamber and to receive therapeutic gas effluent from the dressing; anegative pressure source configured to be coupled to the container suchthat the negative pressure source can be activated to draw fluid fromthe dressing through the chamber of the container, wherein the negativepressure source comprises: an inlet through which gas is received intothe negative pressure source; and an outlet through which gas exits thenegative pressure source; and a diluent gas source coupled to the deviceand configured to deliver a diluent gas to dilute therapeutic gaseffluent before the therapeutic gas effluent enters through the inlet ofthe negative pressure source.

In some embodiments of the present devices, the diluent gas source isconfigured to deliver the diluent gas between the dressing and thechamber. In some embodiments of the present devices, the diluent gassource is configured to deliver the diluent gas between the negativepressure source and the chamber. In some embodiments of the presentdevices, the diluent gas source is configured to deliver the diluent gasto the chamber.

In some embodiments of the present devices, the therapeutic gas sourcecomprises an oxygen source and the therapeutic gas comprises oxygen. Insome embodiments of the present devices, the oxygen source comprises anoxygen concentrator configured to receive atmospheric air and removenitrogen from the air. In some embodiments of the present devices, thediluent gas source is integral with the therapeutic gas source, and thediluent gas comprises the removed nitrogen.

In some embodiments of the present devices, the chamber comprises anoxygen-sorbent material. In some embodiments of the present devices, theoxygen-sorbent material comprises one or more elements selected from thegroup of elements consisting of: iron, sodium chloride, and activatedcarbon. In some embodiments of the present devices, the containercomprises one or more oxygen filters configured to absorb oxygen. Insome embodiments of the present devices, at least one of the one or moreoxygen filters is impregnated with one or more elements selected fromthe group of elements consisting of: pyrogallol, iron, silver chloride,and ascorbic acid. In some embodiments of the present devices, thecontainer comprises a first one-way valve configured to: permitcommunication of gas out of the chamber through the first valve; andprevent communication of gas into the chamber through the first valve.In some embodiments of the present devices, the chamber comprises one ormore baffles, impellers, and/or a screw mixer configured to encouragemixing of the diluent gas and therapeutic gas effluent within thechamber.

In some embodiments of the present devices, the oxygen source isconfigured to provide oxygen to the dressing at a volumetric flow rateof at least 0.25 liters per minute and at a purity of at least 70percent. In some embodiments of the present devices, the oxygen sourceis configured to provide oxygen to the dressing at a volumetric flowrate of approximately 3 to 50 milliliters per hour and at a purity of atleast 70 percent.

In some embodiments of the present devices, the diluent gas sourcecomprises a reservoir containing the diluent gas, wherein the reservoiris configured to be coupled to the container in fluid communication withthe chamber to provide the diluent gas to the chamber. In someembodiments of the present devices, the diluent gas comprises nitrogen.In some embodiments of the present devices, the diluent gas comprisesatmospheric air and the diluent gas source comprises a second one-wayvalve in fluid communication with the chamber and configured to: permitcommunication of the diluent gas into the chamber through the secondvalve; and prevent communication of the diluent gas out of the chamberthrough the second valve.

Some embodiments of the present devices comprise one or more firstconduits configured to be coupled to the first outlet to permit fluidcommunication of therapeutic gas between the therapeutic gas source andthe dressing. Some embodiments of the present devices comprise one ormore second conduits configured to be coupled to the first inlet topermit fluid communication of therapeutic gas effluent between thedressing and the chamber. In some embodiments of the present devices, atleast one of the one or more first conduits and/or at least one of theone or more second conduits comprise one or more valves configured toblock fluid communication in the respective conduit through the valve inresponse to detecting a fire within the respective conduit.

Some embodiments of the present devices comprise one or more thirdconduits configured to be coupled between the diluent gas source and atleast one of the one or more second conduits to permit fluidcommunication of the diluent gas between the diluent gas source and thechamber. Some embodiments of the present devices comprise one or morefourth conduits configured to be coupled between the diluent gas sourceand the container to permit fluid communication of the diluent gasbetween the diluent gas source and the chamber.

Some embodiments of the present devices comprise a second outletconfigured to be in fluid communication with the diluent gas source; oneor more fifth conduits configured to be coupled to the second outlet topermit fluid communication of the diluent gas between the diluent gassource and the dressing.

Some embodiments of the present devices comprise one or more sixthconduits configured to be coupled between the diluent gas source and thenegative pressure source to permit fluid communication of the diluentgas between the diluent gas source and the negative pressure source.

Some embodiments of the present devices comprise a wound irrigationdevice configured to provide wound irrigation fluid to the dressing. Insome embodiments of the present devices, the wound irrigation fluidcomprises one or more elements selected from the group consisting ofsaline, an antimicrobial, and bleach. Some embodiments of the presentdevices comprise a third outlet configured to be in fluid communicationwith the wound irrigation device; one or more seventh conduitsconfigured to be coupled to the third outlet to permit fluidcommunication of wound irrigation fluid between the wound irrigationdevice and the dressing. In some embodiments of the present devices, thewound irrigation device is configured to be in fluid communication withthe first outlet. Some embodiments of the present devices comprise avalve movable between a first position, in which the valve permitstherapeutic gas from the therapeutic gas source through the firstoutlet, and a second position, in which the valve permits woundirrigation fluid from the wound irrigation device through the firstoutlet.

Some embodiments of the present systems comprise a dressing comprising:a gas-occlusive layer configured to be coupled to tissue surroundingtarget tissue such that an interior volume is defined between thegas-occlusive layer and the target tissue; and a body defining one ormore ports configured to provide fluid communication to the interiorvolume through the gas-occlusive layer; a therapeutic gas sourceconfigured to be coupled to the dressing in fluid communication with theinterior volume to provide therapeutic gas to the interior volume; anegative pressure source configured to be coupled to the dressing suchthat the negative pressure source can be activated to draw gas from theinterior volume; and a diluent gas source configured to be coupled tothe system between the interior volume and the negative pressure sourceto deliver a diluent gas to dilute therapeutic gas effluent as or afterthe therapeutic gas effluent flows out of the interior volume.

Some embodiments of the present systems comprise, for at least one ofthe one or more ports, a filter configured to filter fluid that flowsthrough the port. In some embodiments of the present systems, the filtercomprises a layer of material that is bonded to an upper surface or alower surface of the gas-occlusive layer. In some embodiments of thepresent systems, the filter is configured to permit communication oftherapeutic gas effluent out of the interior volume through the port andrestrict communication of exudate out of the interior volume through theport.

Some embodiments of the present systems comprise a dressing comprising:a gas-occlusive layer configured to be coupled to tissue surroundingtarget tissue such that an interior volume is defined between thegas-occlusive layer and the target tissue; and a body defining one ormore ports configured to provide fluid communication to the interiorvolume through the gas-occlusive layer; a therapeutic gas sourceconfigured to be coupled to the dressing in fluid communication with theinterior volume to provide therapeutic gas to the interior volume; acontainer outside the interior volume, the container comprising asidewall that defines a chamber configured to be coupled to the dressingin fluid communication with the interior volume to receive therapeuticgas effluent from the interior volume; a negative pressure sourceconfigured to be coupled to the container such that the negativepressure source can be activated to draw fluid from the interior volumethrough the chamber of the container; and a diluent gas sourceconfigured to be coupled to the system between the interior volume andthe negative pressure source to deliver a diluent gas to dilutetherapeutic gas effluent as or after the therapeutic gas effluent flowsout of the interior volume. In some embodiments of the present systems,the container comprises an outlet in fluid communication with thenegative pressure source, the outlet having a filter configured tofilter fluid that flows through the outlet. In some embodiments of thepresent systems, the filter comprises a layer of material that is bondedto the sidewall of the container. In some embodiments of the presentsystems, the filter is configured to permit communication of therapeuticgas effluent out of the chamber through the outlet and restrictcommunication of exudate out of the chamber through the outlet. In someembodiments of the present systems, the diluent gas source is configuredto be coupled to the system between the dressing and the container.

In some embodiments of the present systems, the diluent gas source isconfigured to be coupled to the system between the container and thenegative pressure source. In some embodiments of the present systems,the diluent gas source is configured to be coupled to the container.

In some embodiments of the present systems, the therapeutic gas sourcecomprises an oxygen source and the therapeutic gas comprises oxygen. Insome embodiments of the present systems, the oxygen source comprises anoxygen concentrator configured to receive atmospheric air and removenitrogen from the air. In some embodiments of the present systems, thediluent gas source is integral with the therapeutic gas source, and thediluent gas comprises the removed nitrogen.

In some embodiments of the present systems, the chamber comprises anoxygen-sorbent material. In some embodiments of the present systems, theoxygen-sorbent material comprises one or more elements selected from thegroup of elements consisting of: iron, sodium chloride, and activatedcarbon. In some embodiments of the present systems, the containercomprises one or more oxygen filters configured to absorb oxygen. Insome embodiments of the present systems, at least one of the one or moreoxygen filters is impregnated with one or more elements selected fromthe group of elements consisting of: pyrogallol, iron, silver chloride,and ascorbic acid.

In some embodiments of the present systems, the oxygen source isconfigured to provide oxygen to the interior volume at a volumetric flowrate of at least 0.25 liters per minute and at a purity of at least 75percent. In some embodiments of the present systems, the oxygen sourceis configured to provide oxygen to the interior volume at a volumetricflow rate of approximately 3 to 50 milliliters per hour and at a purityof at least 75 percent.

In some embodiments of the present systems, the diluent gas sourcecomprises a reservoir containing the diluent gas, wherein the reservoiris configured to be coupled to the container in fluid communication withthe chamber to provide the diluent gas to the chamber. In someembodiments of the present systems, the diluent gas comprises nitrogen.In some embodiments of the present systems, the container comprises afirst one-way valve configured to: permit communication of gas out ofthe chamber through the first valve; and prevent communication of gasinto the chamber through the first valve. In some embodiments of thepresent systems, the diluent gas comprises atmospheric air and thediluent gas source comprises a second one-way valve in fluidcommunication with the chamber and configured to: permit communicationof the diluent gas into the chamber through the second valve; andprevent communication of the diluent gas out of the chamber through thesecond valve.

In some embodiments of the present systems, the chamber comprises one ormore baffles, impellers, and/or a screw mixer configured to encouragemixing of the diluent gas and therapeutic gas effluent within thechamber.

Some embodiments of the present systems comprise one or more firstconduits configured to be coupled between the therapeutic gas source andthe dressing to permit fluid communication of therapeutic gas betweenthe therapeutic gas source and the interior volume. Some embodiments ofthe present systems comprise one or more second conduits configured tobe coupled between the dressing and the container to permit fluidcommunication of therapeutic gas effluent between the interior volumeand the chamber.

In some embodiments of the present systems, at least one of the one ormore first conduits and/or at least one of the one or more secondconduits comprise one or more valves configured to block fluidcommunication in the respective conduit through the valve in response todetecting a fire within the respective conduit. Some embodiments of thepresent systems comprise one or more third conduits configured to becoupled between the diluent gas source and at least one of the one ormore second conduits to permit fluid communication of the diluent gasbetween the diluent gas source and the chamber. Some embodiments of thepresent systems comprise one or more fourth conduits configured to becoupled between the diluent gas source and the container to permit fluidcommunication of the diluent gas between the diluent gas source and thechamber. Some embodiments of the present systems comprise one or morefifth conduits configured to be coupled between the diluent gas sourceand the dressing to permit fluid communication of the diluent gasbetween the diluent gas source and the body defining the one or moreports of the dressing. Some embodiments of the present systems compriseone or more sixth conduits configured to be coupled between the diluentgas source and the negative pressure source to permit fluidcommunication of the diluent gas between the diluent gas source and thenegative pressure source.

In some embodiments of the present systems, the body defining the one ormore ports comprises a valve assembly having: a first inlet configuredto be in fluid communication with the interior volume and to receivetherapeutic gas effluent from the interior volume; a second inletconfigured to be in fluid communication with the diluent gas source toreceive the diluent gas from the diluent gas source; and an outletconfigured be coupled to the container in fluid communication with thechamber to permit fluid communication of the diluent gas and therapeuticgas effluent into the chamber. In some embodiments of the presentsystems, the one or more second conduits is configured to be coupledbetween the container and the outlet to permit fluid communication oftherapeutic gas effluent between the outlet and the chamber of thecontainer; and the one or more fifth conduits is configured to becoupled between the therapeutic gas source and the second inlet topermit fluid communication of the diluent gas between the therapeuticgas source and the second inlet. In some embodiments of the presentsystems, the first inlet comprises a one-way valve configured to: permitcommunication of gas out of the interior volume through the valve; andprevent communication of gas into the interior volume through the valve.

Some embodiments of the present systems comprise a wound irrigationdevice configured to be in fluid communication with the interior volumeto provide wound irrigation fluid to the interior volume. In someembodiments of the present systems, the wound irrigation fluid comprisesone or more elements selected from the group consisting of saline, anantimicrobial, and bleach. Some embodiments of the present systemscomprise one or more seventh conduits configured to be coupled betweenthe wound irrigation device and the dressing to permit fluidcommunication of wound irrigation fluid between the wound irrigationdevice and the interior volume.

Some embodiments of the present methods, for diluting therapeutic gaseffluent flowing from a dressing, comprise coupling a dressing to apatient's tissue, the dressing comprising a gas-occlusive layerconfigured to be coupled to tissue surrounding target tissue such thatan interior volume is defined between the gas-occlusive layer and thetarget tissue; providing therapeutic gas to the interior volume;removing therapeutic gas effluent from the interior volume; and mixingthe removed therapeutic gas effluent with a diluent gas.

In some embodiments of the present methods, the removed therapeutic gaseffluent is mixed with the diluent gas in a container outside theinterior volume. In some embodiments of the present methods, thetherapeutic gas effluent is removed from the interior volume by applyinga negative pressure within the interior volume. In some embodiments ofthe present methods, providing therapeutic gas to the interior volumeand removing therapeutic gas effluent from the interior volume occurssimultaneously. In some embodiments of the present methods, providingtherapeutic gas and removing therapeutic gas effluent occurssimultaneously for a duration of 3 to 4 hours.

Some embodiments of the present methods comprise providing woundirrigation fluid to the interior volume. In some embodiments of thepresent methods, the wound irrigation fluid is provided for a durationof 5 to 15 minutes. Some embodiments of the present methods compriseremoving wound irrigation fluid from the interior volume.

The term “coupled” is defined as connected, although not necessarilydirectly, and not necessarily mechanically; two items that are “coupled”may be unitary with each other. The terms “a” and “an” are defined asone or more unless this disclosure explicitly requires otherwise. Theterm “substantially” is defined as largely but not necessarily whollywhat is specified (and includes what is specified; e.g., substantially90 degrees includes 90 degrees and substantially parallel includesparallel), as understood by a person of ordinary skill in the art. Inany disclosed embodiment, the term “substantially” may be substitutedwith “within [a percentage] of” what is specified, where the percentageincludes 0.1, 1, 5, and 10 percent.

The phrase “and/or” means and or. The phrase “and/or” includes any andall combinations of one or more of the associated listed items. Toillustrate, A, B, and/or C includes: A alone, B alone, C alone, acombination of A and B, a combination of A and C, a combination of B andC, or a combination of A, B, and C. In other words, “and/or” operates asan inclusive or.

The terms “comprise” (and any form of comprise, such as “comprises” and“comprising”), “have” (and any form of have, such as “has” and“having”), and “include” (and any form of include, such as “includes”and “including”) are open-ended linking verbs. As a result, an apparatusthat “comprises,” “has,” or “includes” one or more elements possessesthose one or more elements, but is not limited to possessing only thoseelements. Likewise, a method that “comprises,” “has,” or “includes,” oneor more steps possesses those one or more steps, but is not limited topossessing only those one or more steps.

Any embodiment of any of the apparatuses, systems, and methods canconsist of or consist essentially of—rather thancomprise/have/include—any of the described steps, elements, and/orfeatures. Thus, in any of the claims, the term “consisting of” or“consisting essentially of” can be substituted for any of the open-endedlinking verbs recited above, in order to change the scope of a givenclaim from what it would otherwise be using the open-ended linking verb.

The feature or features of one embodiment may be applied to otherembodiments, even though not described or illustrated, unless expresslyprohibited by this disclosure or the nature of the embodiments.

Further, an apparatus that is configured in a certain way is configuredin at least that way, but it can also be configured in other ways thanthose specifically described.

Some details associated with the embodiments are described above, andothers are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings illustrate by way of example and not limitation.For the sake of brevity and clarity, every feature of a given structureis not always labeled in every figure in which that structure appears.Identical reference numbers do not necessarily indicate an identicalstructure. Rather, the same reference number may be used to indicate asimilar feature or a feature with similar functionality, as maynon-identical reference numbers. The figures are drawn to scale (unlessotherwise noted), meaning the sizes of the depicted elements areaccurate relative to each other for at least the embodiment depicted inthe figures. Figures having schematic views are not drawn to scale.

FIG. 1 is a schematic view of a first embodiment of the present systems.

FIG. 2 is a schematic view of a second embodiment of the presentsystems.

DETAILED DESCRIPTION

Referring to FIG. 1, shown therein and designated by the referencenumeral 10 is one embodiment of the present systems for providingtopical wound therapy. System 10 includes a wound therapy device 14 anda wound dressing 18 configured to be coupled to target tissue 22 and/orto tissue 30 surrounding the target tissue to facilitate delivery oftherapeutic gas to the target tissue.

The term “target tissue” as used herein can broadly refer to a wound(e.g., open or closed), a tissue disorder, and/or the like located on orwithin tissue, such as, for example, bone tissue, adipose tissue, muscletissue, neural tissue, dermal tissue, vascular tissue, connectivetissue, cartilage, tendons, ligaments, and/or the like. The term “targettissue” as used herein can also refer to areas of tissue that are notnecessarily wounded or exhibit a disorder, but include tissue that wouldbenefit from tissue generation. The term “wound” as used herein canrefer to a chronic, subacute, acute, traumatic, and/or dehiscedincision, laceration, puncture, avulsion, and/or the like, apartial-thickness and/or full thickness burn, an ulcer (e.g., diabetic,pressure, venous, and/or the like), flap, and/or graft.

Dressing 18 can include one or more manifolds 46 configured to allowcommunication of therapeutic gas to target tissue 22 and/or allowcommunication of exudate away from the target tissue. Manifold 46 can beconfigured to be in contact with target tissue 22. For example, manifold46 may be disposed over target tissue 22 such that the manifold fills atleast a portion of a recess defined by the target tissue.

Manifold 46 may be porous. For example, each manifold 46 can define aplurality of gas passageways 50 to distribute therapeutic gas across themanifold, to collect exudate from target tissue 22 across the manifold,and/or to promote granulation of the target tissue. Each gas passageway50 can comprise a width ranging approximately 400 to approximately 600microns. Plurality of gas passageways 50 of each manifold 46 can beinterconnected to improve distribution and/or collection of fluidsacross the manifold. For example, gas passageways 50 can be defined byan open-cell foam (e.g., reticulated foam), tissue paper, gauze, anon-woven textile (e.g., felt), and/or the like.

Manifold 46 can comprise any suitable material, such as, for example,polyethylene, a polyolefin, a polyether, polyurethane, a co-polyester, acopolymer thereof, or a blend thereof. For example, in embodiments wheremanifold 46 comprises a foam, such a foam may be polyether-basedpolyurethane foam. Manifold 46 can comprise any suitable planform shape,planform area, thickness, and/or the like that is appropriate to treattarget tissue 22.

A non-limiting example of manifold 46 includes GRANUFOAM™ Dressings,which are commercially available from Kinetic Concepts Inc., of SanAntonio, Tex., USA.

Dressing 18 can include a gas-occlusive layer 74. Gas-occlusive layer 74can be configured to be disposed over one or more manifolds 46 andcoupled to tissue 30 surrounding target tissue 22 such that an interiorvolume 78 is defined between the gas-occlusive layer and the targettissue. Gas-occlusive layer 74 can be coupled to tissue 30 surroundingtarget tissue 22 such that the gas-occlusive layer 74 limits the escapeof therapeutic gas and/or exudate from interior volume 78 between thegas-occlusive layer and the tissue surrounding the target tissue. Forexample, a tissue-facing surface of gas-occlusive layer 74 can comprisean adhesive, such as, for example, an acrylic adhesive, polyurethane geladhesive, silicone adhesive, a combination thereof, and/or the like,configured to couple the gas-occlusive layer to tissue 30 surroundingtarget tissue 22.

Gas-occlusive layer 74 may comprise a flexible film, such as, forexample, a hydrocolloid sheet. Gas-occlusive layer 74 can comprise anysuitable material that limits escape of therapeutic gas and/or exudatethrough the gas-occlusive layer, such as, for example, polyurethane,polyethylene, polyvinyl acetate, polyvinyl chloride, polyvinylidenechloride, isobutylene, a halogenated isomer (e.g., chlorobutyl and/orbromobutyl), epichlorohydrin, a copolymer thereof, or a blend thereof.Gas-occlusive layer 74 can comprise any suitable planform shape,planform area, thickness, and/or the like that is appropriate to treattarget tissue 22. For example, gas-occlusive layer 74 can comprise athickness that is approximately any one of, or between approximately anytwo of the following: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60micrometers.

Gas-occlusive layer 74 can comprise one or more openings 98 configuredto permit communication of therapeutic gas into and/or therapeutic gaseffluent out of interior volume 78 of dressing 18. One or more openings98 may be configured to permit communication of exudate out of interiorvolume 78 of dressing 18.

Device 14 can comprise a housing 102 configured to hold a therapeuticgas source 106, a diluent gas source 112, a container 114, a negativepressure source 118, and, optionally, a wound irrigation device 122.

Therapeutic gas source 106 can be configured to provide therapeutic gasto dressing 18. More particularly, therapeutic gas source can beconfigured to be coupled to dressing 18 in fluid communication withinterior volume 78 to provide therapeutic gas to the interior volume.For example, device 14 comprises a first outlet 126 configured to be influid communication with therapeutic gas source 106. System 10 cancomprise one or more therapeutic gas (“TG”) conduits 130 configured tobe coupled between therapeutic gas source 106 and dressing 18 to permitfluid communication of therapeutic gas between the therapeutic gassource and interior volume 78. For example, TG conduit(s) 130 can beconfigured to be coupled to first outlet 126 of device 14 to permitfluid communication of therapeutic gas between therapeutic gas source106 and dressing 18.

Dressing 18 may comprise a body 134 defining one or more outlet ports 94a and one or more inlet ports 94 b configured to provide fluidcommunication to interior volume 78 through gas-occlusive layer 74. Forexample, therapeutic gas can be delivered to interior volume 78 viainlet port(s) 94 b of body 134. More particularly, inlet port(s) 94 b ofbody 134 may have a first inlet 138 configured to be in fluidcommunication with interior volume 78 and to receive therapeutic gasfrom therapeutic gas source 106. For example, first inlet 138 cancomprise a one-way valve 142 configured to permit communication oftherapeutic gas into interior volume 78 through the valve and preventcommunication of therapeutic gas out of the interior volume through thevalve.

Therapeutic gas may be introduced into interior volume 78 to treattarget tissue 22. After sufficient exposure to target tissue 22,therapeutic gas within interior volume 78 may be removed from theinterior volume—the removed therapeutic gas is called “therapeutic gaseffluent.” For example, therapeutic gas effluent can be removed frominterior volume 78 via outlet port(s) 94 a of body 134. Moreparticularly, outlet port(s) 94 a of body 134 may have an outlet 146configured to be in fluid communication with interior volume 78 and topermit flow of therapeutic gas effluent and/or exudate out of theinterior volume. For example, outlet 146 can comprise a one-way valve150 configured to permit communication of therapeutic gas effluentand/or exudate out of interior volume 78 through the valve and preventcommunication of fluid into the interior volume through the valve.

Body 134 can be configured to be releasably coupled to wound therapydevice 14 and/or dressing 18 such that the device can be decoupled fromthe dressing without removing the dressing from target tissue 22 and/ortissue 30 surrounding the target tissue. For example, an adhesiveapplied to body 134 may seal the body around opening 98 of gas-occlusivelayer 74 in order to minimize the diffusion of fluid between the bodyand the gas-occlusive layer.

A non-limiting example of body 134 includes the T.R.A.C.™ Pad, which iscommercially available from Kinetic Concepts Inc., of San Antonio, Tex.,USA.

Therapeutic gas source 106 can be configured to supply therapeutic gasto dressing 18 at a volumetric flow rate of at least approximately 0.25liters per minute (L/min), such as, for example, at least approximatelyany one of, or between approximately any two the following: 0.25, 1, 2,3, 4, 5, 10, 20, 30, 40, and 50 L/min. Therapeutic gas source 106 can beconfigured to supply any gas, such as, for example, oxygen, that issuitable for treating target tissue 22. Therapeutic gas supplied bytherapeutic gas source 106 can comprise a high oxygen concentration,such as an oxygen concentration of at least 70 percent (e.g., 70, 75,80, 85, 90, 92, 94, 96, 98, 99, 99.9, 99.99 or more percent). At leastdue to the high concentration of oxygen within therapeutic gas, whichcan act as an accelerant to an open flame, system 10 is configured todilute therapeutic gas effluent to reduce the purity of oxygen as orafter the effluent is removed from interior volume 78, as described infurther detail below. In this way and others, system 10 improves thesafety of topical high-purity oxygen wound therapy.

Therapeutic gas source 106 can comprise any suitable device configuredto supply therapeutic gas to dressing 18 at one or more of thevolumetric flow rates and/or oxygen concentrations described herein,such as, for example, an electrolytic oxygen source (e.g., an oxygenconcentrator), a liquid oxygen reservoir, a reservoir having compressedoxygen gas, and/or the like. In embodiments where therapeutic gas source106 comprises an oxygen concentrator, the therapeutic gas source may beconfigured to receive atmospheric air and remove nitrogen from the air(e.g., via one or more filters and/or sieve beds).

Device 14 includes a negative pressure source 118 configured to be influid communication with dressing 18 such that the negative pressuresource can be activated to draw fluid from interior volume 78. Forexample, negative pressure source 118 includes an inlet 154 throughwhich gas is received into the negative pressure source and an outlet158 through which gas exits the negative pressure source. Negativepressure source 118 can be configured to provide negative pressurewithin interior volume 78 of dressing 18 such that the volume of theinterior volume is reduced and/or negative pressure is applied to targettissue 22 and/or tissue 30 surrounding the target tissue to improvewound healing and/or sealing between the dressing and tissue surroundingthe target tissue. As used herein, “negative pressure” can refer to apressure that is less than a local ambient pressure, such as less thanatmospheric pressure. Negative pressure source 118 can comprise areservoir of gas held at a negative pressure. Negative pressure source118 may comprise a mechanically and/or electrically-powered device, suchas, for example, a vacuum pump, a suction pump, a wall suction port, amicro-pump, and/or the like that can reduce pressure within dressing 18and/or a container (e.g., 114).

In some embodiments, device 14 can comprise a container 114. Forexample, container 114 comprises a sidewall 162 that defines a chamber166 configured to receive therapeutic gas effluent and/or exudate fromdressing 18. As shown in FIG. 1, container 114 is disposed outside ofinterior volume 78.

Chamber 166 can be configured to be coupled to dressing 18 in fluidcommunication with interior volume 78 to receive therapeutic gaseffluent and/or exudate from the interior volume. For example, device 14can include a first inlet 170 configured to be in fluid communicationwith chamber 166 and to receive therapeutic gas effluent and/or exudatefrom dressing 18. System 10 may comprise one or more effluent conduits174 configured to be coupled between dressing 18 and container 114(e.g., between interior volume 78 and chamber 166) to permit fluidcommunication between the interior volume and the chamber. For example,effluent conduit(s) 174 may be configured to be coupled between and/orto container 114 and/or outlet port(s) 94 a of body 134 to permit fluidcommunication between the outlet port(s) and chamber 166 of thecontainer. Further, effluent conduit(s) 174 can be configured to becoupled to first inlet 170 of device 14 to permit fluid communicationbetween dressing 18 and chamber 166.

Negative pressure source 118 can be configured to be coupled tocontainer 114 such that, when the negative pressure source is activated,the negative pressure source draws fluid from dressing 18, and moreparticularly, from interior volume 78, through chamber 166 of thecontainer to inlet 154 of the negative pressure source.

Container 114 can comprise an outlet 178 configured to be in fluidcommunication with inlet 154 of negative pressure source 118 via one ormore conduits 182. Outlet 178 of container 114 can comprise a one-waycheck valve 186 configured to permit communication of gas out of chamber166 through the valve and prevent communication of gas into the chamberthrough the valve. Outlet 178 can comprise a filter 110 configured tofilter fluid that flows through the outlet. For example, filter 110 canbe sterile such that the filter provides a viral and/or bacterialbarrier. Filter 110 can comprise a layer of material that is bonded tosidewall 162 of container 114. Filter 110 can comprise any suitablematerial, such as, for example, polytetrafluoroethylene (PTFE) (e.g., anexpanded PTFE), a polyester, a polyamide, polyolefin, a copolymerthereof, a blend thereof, and/or the like. Filter 110 can have a backingmaterial, such as, for example, a non-woven textile, comprising apolyester, a polyamide, and/or the like. Filter 110 may comprise ahydrophobic material. To illustrate, filter 110 can be configured toallow communication of therapeutic gas effluent out of chamber 166through outlet 178 and restrict communication of liquid exudate out ofthe chamber through the outlet. In at least this way, filter 110prevents liquid exudate from flowing to negative pressure source 118.Instead, liquid exudate remains within chamber 166 of container 114.

Filter 110 can comprise a pore size of approximately 0.05 to 0.15micrometers (e.g., approximately any one of or between any two of thefollowing: 0.05, 0.07, 0.09, 0.10, 0.11, 0.13, and 0.15 micrometers). Anon-limiting example of filter 110 includes GORE® Microfiltration Mediafor Medical Devices, which is commercially available from W. L. Gore &Associates, Inc., of Newark, Del., USA.

Device 14 comprises a diluent gas source 112 configured to be coupled tosystem 10 (e.g., coupled to one or more components of device 14) betweeninterior volume 78 and negative pressure source 118 to deliver a diluentgas to dilute therapeutic gas effluent as or after the therapeutic gaseffluent flows out of the interior volume, but before the therapeuticgas effluent enters inlet 154 of the negative pressure source. As shownin FIG. 1, diluent gas source 112 can be configured to deliver diluentgas to one or more conduits (e.g., 174 and/or 182), to body 134, and/ordirectly to container 114 to dilute therapeutic gas effluent flowingfrom interior volume 78.

Diluent gas source 112 can comprise any suitable device configured todeliver a substance, such as, for example, nitrogen gas, that reducesthe purity of oxygen within therapeutic gas effluent. For example,diluent gas source can comprise a reservoir containing diluent gas. Sucha reservoir can be configured to be coupled to container 114 in fluidcommunication with chamber 166 to provide diluent gas to the chamber. Inembodiments where therapeutic gas source 106 comprises an oxygenconcentrator configured to remove nitrogen from atmospheric air, diluentgas source 112 may be integral with the therapeutic gas source such thatthe diluent gas provided by the diluent gas source comprises thenitrogen removed by the therapeutic gas source.

As shown in FIG. 1, diluent gas source 112 can be configured to deliverdiluent gas between dressing 18 (e.g., interior volume 78) and container114 (e.g., chamber 166). For example, system 10 can comprise one or morefirst diluent conduits 190 configured to be coupled between diluent gassource 112 and at least one of effluent conduit(s) 174 to permit fluidcommunication of diluent gas between the diluent gas source and chamber166. As shown in FIG. 1, first diluent conduit(s) 190 can be containedwithin housing 102 of device 14. Therapeutic gas effluent withineffluent conduit(s) 174 can mix with diluent gas supplied by diluent gassource 112 (e.g., via first diluent conduit(s) 190) to reduce the purityof oxygen within therapeutic gas effluent. In this way and others, theconcentration of oxygen within therapeutic gas effluent can be reducedto approximately 20 percent before the mixture of therapeutic gaseffluent and diluent gas enters inlet 154 of negative pressure source118.

Device 14 can include a second outlet 194 configured to be in fluidcommunication with diluent gas source 112. For example, system 10 caninclude one or more second diluent conduits 198 configured to be coupledbetween diluent gas source 112 and dressing 18 (e.g., coupled to secondoutlet 194 and/or to outlet port(s) 94 a of body 134) to permit fluidcommunication of diluent gas between diluent gas source 112 and dressing14 (e.g., the body). For example, outlet port(s) 94 a comprises an inlet202 configured to be in fluid communication with interior volume 78 andto receive therapeutic gas effluent from the interior volume. Forexample, first inlet 202 can comprise a one-way valve configured topermit communication of fluid (e.g., therapeutic gas effluent and/orexudate) out of interior volume 78 through the valve and preventcommunication of fluid into the interior volume through the valve.Outlet port(s) 94 a can comprise a second inlet 206 having a one-wayvalve 210 configured to be in fluid communication with diluent gassource 112 to receive diluent gas from the diluent gas source. Outletport(s) 94 a can be configured to allow fluid through first inlet 202and second inlet 206 simultaneously such that, as therapeutic gaseffluent and/or exudate exit interior volume 78 (e.g., via the firstinlet of the outlet port(s)), the therapeutic gas effluent mixes withdiluent gas supplied by diluent gas source 112 (e.g., via the secondinlet of the outlet port(s)) to reduce the purity of oxygen withintherapeutic gas effluent. Thereafter, the resulting mixture of diluentgas, therapeutic gas effluent, and exudate can flow through outlet 146of outlet port(s) 94 a toward chamber 166 of container 114, where thetherapeutic gas effluent and the diluent gas can be separated from theexudate (e.g., via filter 110). In this way and others, theconcentration of oxygen within therapeutic gas effluent is reduced toapproximately 20 percent before the mixture of therapeutic gas effluentand diluent gas enters inlet 154 of negative pressure source 118.

As shown in FIG. 1, diluent gas source 112 can be configured to deliverdiluent gas between negative pressure source 118 and chamber 166 ofcontainer 114. For example, system 10 may include one or more thirddiluent conduits 214 configured to be coupled between diluent gas source112 and conduit(s) 182 between container 114 and negative pressuresource 118 to permit fluid communication of diluent gas between diluentgas source 112 and therapeutic gas effluent exiting outlet 178 ofcontainer 114. For example, therapeutic gas effluent within conduit(s)182 can mix with diluent gas supplied by diluent gas source 112 (e.g.,via third diluent conduit(s) 214) to reduce the purity of oxygen withintherapeutic gas effluent. In this way and others, the concentration ofoxygen within therapeutic gas effluent can be reduced to approximately20 percent before the mixture of therapeutic gas effluent and diluentgas enters inlet 154 of negative pressure source 118.

Diluent gas source 112 can be configured to deliver diluent gas tochamber 166 (e.g., without any intermediary conduit(s) (e.g., 174)and/or port(s) (e.g., 94 a and/or 94 b)). As shown, diluent gas source112 can be configured to be coupled to container 114. For example,system 10 can comprise one or more fourth diluent conduits 218configured to be coupled between diluent gas source 112 and container114 to permit fluid communication of diluent gas between the diluent gassource and chamber 166.

Container 114 may be configured to encourage the dilution of therapeuticgas effluent within chamber 166 at least by encouraging the mixing ofdiluent gas and therapeutic gas effluent within the chamber. Forexample, chamber 166 can comprise one or more baffles, impellers, ascrew mixer, and/or the like to encourage mixing of diluent gas andtherapeutic gas effluent within the chamber, thereby diluting thetherapeutic gas effluent (i.e., decreasing the purity of oxygen withingas that exits outlet 178 of container 114). Container 114 may includean oxygen-sorbent material 222 disposed within chamber 166 to encouragethe dilution of therapeutic gas effluent within the chamber. Forexample, oxygen-sorbent material 222 can comprise one or more elementsselected from the group of elements consisting of: iron, sodiumchloride, and activated carbon. Further, container 114 may include oneor more oxygen filters 226 within chamber 166 to absorb oxygen, therebydiluting therapeutic gas effluent within the chamber. At least one ofoxygen filter(s) 226 can be impregnated with one or more elementsselected from the group of elements consisting of: pyrogallol, iron,silver chloride, ascorbic acid, and/or the like, to dilute therapeuticgas effluent within chamber 166.

In some embodiments, diluent gas comprises atmospheric air to dilutetherapeutic gas effluent. For example, system 10 may comprise one ormore openings, each of which may be filtered (e.g., 110) and exposed toatmospheric air such that, when negative pressure source 118 isactivated to draw fluid (e.g., therapeutic gas effluent and/or exudate)from interior volume 78, the negative pressure source draws atmosphericair into one or more conduit(s) (e.g., 174, 182, 190, 214, 218), intodiluent gas source 112, and/or into chamber 166, via the filteredopenings. For example, diluent gas source 112 can comprise a one-wayvalve 230 in fluid communication with chamber 166 and configured topermit communication of diluent gas (e.g., atmospheric air) into thechamber through the valve and prevent communication of the diluent gasout of the chamber through the valve. For further example, container 114can comprise a one-way valve 234 in fluid communication with chamber 166and configured to permit communication of diluent gas (e.g., atmosphericair) into the chamber through the valve and prevent communication of thediluent gas out of the chamber through the valve.

System 10 can comprise one or more safety features configured to preventthe propagation of fire in the event conduit(s) 130, 174, 182, carryingtherapeutic gas and/or therapeutic gas effluent catch fire. For example,at least one of TG conduit(s) 130 and/or effluent conduit(s) 174 cancomprise one or more safety valves 238 configured to block fluidcommunication in the respective conduit through the valve in response todetecting a fire within the respective conduit. Each safety valve 238may block fluid communication in a respective conduit (e.g., 130, 174)by having a material that melts in response to a temperature within theconduit exceeding a threshold level. The melted material can beconfigured to block fluid flow through the respective conduit. In thisway and others, valve(s) 238 can reduce the risk of a fire reachingtherapeutic gas source 106, can reduce the rate at which a fire spreadsalong TG and effluent conduit(s) 130, 174, and/or the like.

Optionally, device 14 can include a wound irrigation device 122configured to provide wound irrigation fluid to dressing 18. Such awound irrigation fluid can comprise any suitable substance configured tosterilize and/or disinfect target tissue 22, such as, for example, oneor more elements selected from the group consisting of saline, anantimicrobial, and bleach. Wound irrigation device 122 may be configuredto be in fluid communication with interior volume 78 to provide woundirrigation fluid to the interior volume. More particularly, device 14may comprise a third outlet 242 configured to be in fluid communicationwith wound irrigation device 122. System 10 may comprise one or moreirrigation conduits 246 configured to be coupled between woundirrigation device 122 and dressing 18, such as, for example, via thirdoutlet 242, to permit fluid communication of wound irrigation fluidbetween wound irrigation device 122 and dressing 18 (e.g., interiorvolume 78). For example, inlet port(s) 94 b of body 134 may comprise asecond inlet 250 configured to be in fluid communication with interiorvolume 78 and to receive wound irrigation fluid from wound irrigationdevice 122. For example, second inlet 250 can comprise a one-way valve254 configured to permit communication of wound irrigation fluid intointerior volume 78 through the valve and prevent communication of fluidout of the interior volume through the valve.

In some embodiments, first outlet 126 and third outlet 242 of device 14may be integral and incorporated into a single outlet (e.g., 126) havinga valve movable between a first position, in which the valve permitstherapeutic gas from therapeutic gas source 106 through the outlet, anda second position, in which the valve permits wound irrigation fluidfrom wound irrigation device 122 through the outlet.

Referring now to FIG. 2, shown therein and designated by the referencenumeral 10 a is a second embodiment of the present systems. System 10 ais substantially similar to system 10, with the primary exception thatsystem 10 a does not have a container (e.g., 144) within housing 102 ofdevice 14. As shown, system 10 a comprises a dressing 18 a that issubstantially similar to dressing 18, with the primary exception thatdressing 18 a comprises a filter 110 a, which is substantially similarto filter 110. Filter 110 a can be coupled to an upper surface or alower surface of gas occlusive layer 74. One or more outlet port(s) 94 aof body 134 may comprise filter 110 a. Filter 110 a is configured tofilter fluid that flows through outlet port(s) 94 a. Filter 110 a isconfigured to permit communication of therapeutic gas effluent out ofinterior volume 78 through port(s) 94 a and restrict communication ofexudate out of the interior volume through the port(s). As shown,negative pressure source 118 can be configured to be in fluidcommunication with dressing 18 a such that the negative pressure sourcecan be activated to draw therapeutic gas effluent from interior volume78. In other words, filter 110 a of dressing 18 a can prevent exudatefrom flowing out of interior volume 78, and thereby prevent exudate fromflowing to negative pressure source 23.

Some embodiments of the present methods for diluting therapeutic gaseffluent flowing from a dressing (e.g., 18) coupling a dressing (e.g.,18) to a patient's tissue (e.g., 22 or 30), the dressing comprising agas-occlusive layer (e.g., 74) configured to be coupled to tissue e.g.,30) surrounding target tissue (e.g., 22) such that an interior volume(e.g., 78) is defined between the gas-occlusive layer and the targettissue; providing therapeutic gas to the interior volume; removingtherapeutic gas effluent from the interior volume; and mixing theremoved therapeutic gas effluent with a diluent gas.

In some embodiments of the present methods, the removed therapeutic gaseffluent is mixed with the diluent gas in a container (e.g., 114)outside the interior volume. In some embodiments of the present methods,the therapeutic gas effluent is removed from the interior volume byapplying a negative pressure within the interior volume. In someembodiments of the present methods, providing therapeutic gas to theinterior volume and removing therapeutic gas effluent from the interiorvolume occurs simultaneously. In some embodiments of the presentmethods, providing therapeutic gas and removing therapeutic gas effluentoccurs simultaneously for a duration of 3 to 4 hours. Some embodimentsof the present methods comprise providing wound irrigation fluid to theinterior volume. In some embodiments of the present methods, the woundirrigation fluid is provided for a duration of 5 to 15 minutes. Someembodiments of the present methods comprise removing wound irrigationfluid from the interior volume.

The above specification and examples provide a complete description ofthe structure and use of illustrative embodiments. Although certainembodiments have been described above with a certain degree ofparticularity, or with reference to one or more individual embodiments,those skilled in the art could make numerous alterations to thedisclosed embodiments without departing from the scope of thisinvention. As such, the various illustrative embodiments of the methodsand systems are not intended to be limited to the particular formsdisclosed. Rather, they include all modifications and alternativesfalling within the scope of the claims, and embodiments other than theone shown may include some or all of the features of the depictedembodiment. For example, elements may be omitted or combined as aunitary structure, and/or connections may be substituted. Further, whereappropriate, aspects of any of the examples described above may becombined with aspects of any of the other examples described to formfurther examples having comparable or different properties and/orfunctions, and addressing the same or different problems. Similarly, itwill be understood that the benefits and advantages described above mayrelate to one embodiment or may relate to several embodiments.

The claims are not intended to include, and should not be interpreted toinclude, means-plus- or step-plus-function limitations, unless such alimitation is explicitly recited in a given claim using the phrase(s)“means for” or “step for,” respectively.

1. A device configured to dilute therapeutic gas effluent flowing from adressing, the device comprising: a therapeutic gas source configured toprovide therapeutic gas to the dressing; a first outlet configured to bein fluid communication with the therapeutic gas source; a containercomprising a sidewall that defines a chamber configured to receivetherapeutic gas effluent from the dressing; a first inlet configured tobe in fluid communication with the chamber and to receive therapeuticgas effluent from the dressing; a negative pressure source configured tobe coupled to the container such that the negative pressure source canbe activated to draw fluid from the dressing through the chamber of thecontainer, wherein the negative pressure source comprises: an inletthrough which gas is received into the negative pressure source; and anoutlet through which gas exits the negative pressure source; and adiluent gas source coupled to the device and configured to deliver adiluent gas to dilute therapeutic gas effluent before the therapeuticgas effluent enters through the inlet of the negative pressure source.2-4. (canceled)
 5. The device of claim 1, wherein the therapeutic gassource comprises an oxygen source and the therapeutic gas comprisesoxygen.
 6. The device of claim 5, wherein the oxygen source comprises anoxygen concentrator configured to receive atmospheric air and removenitrogen from the air.
 7. The device of claim 6, wherein the diluent gassource is integral with the therapeutic gas source, and the diluent gascomprises the removed nitrogen.
 8. The device of claim 5, wherein thechamber comprises an oxygen-sorbent material having one or more elementsselected from the group of elements consisting of: iron, sodiumchloride, and activated carbon.
 9. (canceled)
 10. The device of claim 5,wherein the container comprises one or more oxygen filters configured toabsorb oxygen, the one or more oxygen filters being impregnated with oneor more elements selected from the group of elements consisting of:pyrogallol, iron, silver chloride, and ascorbic acid. 11-13. (canceled)14. The device of claim 1, where the diluent gas source comprises areservoir containing the diluent gas, wherein the reservoir isconfigured to be coupled to the container in fluid communication withthe chamber to provide the diluent gas to the chamber.
 15. The device ofclaim 1, wherein the diluent gas comprises nitrogen. 16-19. (canceled)20. The device of claim 1, comprising one or more effluent conduitsconfigured to be coupled to the first inlet to permit fluidcommunication of therapeutic gas effluent between the dressing and thechamber.
 21. (canceled)
 22. The device of claim 20, comprising one ormore first diluent conduits configured to be coupled between the diluentgas source and at least one of the one or more effluent conduits topermit fluid communication of the diluent gas between the diluent gassource and the chamber.
 23. The device of claim 1, comprising one ormore second diluent conduits configured to be coupled between thediluent gas source and the container to permit fluid communication ofthe diluent gas between the diluent gas source and the chamber.
 24. Thedevice of claim 1, comprising: a second outlet configured to be in fluidcommunication with the diluent gas source; one or more third diluentconduits configured to be coupled to the second outlet to permit fluidcommunication of the diluent gas between the diluent gas source and thedressing.
 25. The device of claim 1, comprising one or more fourthdiluent conduits configured to be coupled between the diluent gas sourceand the negative pressure source to permit fluid communication of thediluent gas between the diluent gas source and the negative pressuresource.
 26. The device of claim 1, comprising a wound irrigation deviceconfigured to provide wound irrigation fluid to the dressing. 27-34.(canceled)
 35. A system comprising: a dressing comprising: agas-occlusive layer configured to be coupled to tissue surroundingtarget tissue such that an interior volume is defined between thegas-occlusive layer and the target tissue; and a body defining one ormore ports configured to provide fluid communication to the interiorvolume through the gas-occlusive layer; a therapeutic gas sourceconfigured to be coupled to the dressing in fluid communication with theinterior volume to provide therapeutic gas to the interior volume; acontainer outside the interior volume, the container comprising asidewall that defines a chamber configured to be coupled to the dressingin fluid communication with the interior volume to receive therapeuticgas effluent from the interior volume; a negative pressure sourceconfigured to be coupled to the container such that the negativepressure source can be activated to draw fluid from the interior volumethrough the chamber of the container; and a diluent gas sourceconfigured to be coupled to the system between the interior volume andthe negative pressure source to deliver a diluent gas to dilutetherapeutic gas effluent as or after the therapeutic gas effluent flowsout of the interior volume. 36-55. (canceled)
 56. The system of claim35, comprising one or more therapeutic gas conduits configured to becoupled between the therapeutic gas source and the dressing to permitfluid communication of therapeutic gas between the therapeutic gassource and the interior volume.
 57. The system of claim 35, comprisingone or more effluent conduits configured to be coupled between thedressing and the container to permit fluid communication of therapeuticgas effluent between the interior volume and the chamber. 58-60.(canceled)
 61. The system of claim 35, comprising one or more diluentconduits configured to be coupled between the diluent gas source and thedressing to permit fluid communication of the diluent gas between thediluent gas source and the body defining the one or more ports of thedressing.
 62. (canceled)
 63. The system of claim 61, wherein the bodydefining the one or more ports comprises a valve assembly having: afirst inlet configured to be in fluid communication with the interiorvolume and to receive therapeutic gas effluent from the interior volume;a second inlet configured to be in fluid communication with the diluentgas source to receive the diluent gas from the diluent gas source; andan outlet configured be coupled to the container in fluid communicationwith the chamber to permit fluid communication of the diluent gas andtherapeutic gas effluent into the chamber.
 64. The system of claim 63,wherein: the one or more effluent conduits is configured to be coupledbetween the container and the outlet to permit fluid communication oftherapeutic gas effluent between the outlet and the chamber of thecontainer; and the one or more diluent conduits is configured to becoupled between the therapeutic gas source and the second inlet topermit fluid communication of the diluent gas between the therapeuticgas source and the second inlet. 65-68. (canceled)
 69. A method fordiluting therapeutic gas effluent flowing from a dressing, the methodcomprising: coupling a dressing to a patient's tissue, the dressingcomprising a gas-occlusive layer configured to be coupled to tissuesurrounding target tissue such that an interior volume is definedbetween the gas-occlusive layer and the target tissue; providingtherapeutic gas to the interior volume; removing therapeutic gaseffluent from the interior volume; and mixing the removed therapeuticgas effluent with a diluent gas.
 70. The method of claim 69, wherein theremoved therapeutic gas effluent is mixed with the diluent gas in acontainer outside the interior volume.
 71. (canceled)
 72. The method ofclaim 69, wherein providing therapeutic gas to the interior volume andremoving therapeutic gas effluent from the interior volume occurssimultaneously.
 73. (canceled)
 74. The method of claim 69, comprisingproviding wound irrigation fluid to the interior volume.
 75. (canceled)76. (canceled)
 77. The device of claim 1, wherein the diluent gascomprises atmospheric air.